Oil burner controls



OIL BURNER CONTROLS Filed May 5l, 1930 ko mg oooooo -GOOOOOOGO OOOOGOOOOO V-OGO ooo'o gu/enger @MMZz/gsgm 79 WW Patented Apr.l 24, 1934 UNITED STATES OIL BURNER CONTROLSV K Gustaf W. Engstrom, Riverside, Ill., assignor to International Harvester Company, a corporation of New Jersey Application May a1, 1930, serial No. 457,874

3 Claims.

This invention relates to a combustion system. More specifically it relates to controlling means for a high pressure, semi-flash boiler and its -heat supplying burner.

The principal object of the invention is to provide an improved controlling means adapted to be automatically operated by the temperature and pressure in the boiler fluid. f

Another object is to provide means for automatically controlling the fuel and air supply to the main burner and'to the pilot burner.

Other objects will be 'apparent from the detailed description to follow.

The drawing represents diagrammatioally a steam generating and consuming system of the semi-flash type in which the invention is embodied.

A hot well 1 supplies water through a pipe 2 to a high pressure feed water pump 3. From the discharge side of the pump water is forcedat a pressure higher than the pressure at which the boiler operates through a pipe 4 to a preheating coil 5. From the preheating coil, the water is forced through a pipe 6 and an injector nozzle 7 into a pipe 8. A pipe 9 connects the pipe 8with a water storage drum 10. By the injector action, water from the storage drum is entrained with the preheated water and forced through the vaporizing coil 11 where a portion of the water is converted into steam. From coil 11, the mixture of Water and steam is discharged through a pipe 12 into the upper portion of the storage drum 10 above the liquid level therein. The discharge is tangential whereby the steam and water are separated. Steam from the storage drum is withdrawn through a pipe 13 and conducted through a superheating coil 14. A pipe 15 connects the superheating coil with a steam consuming means, such as the engine 16 shown in the drawing. Exhaust steam from the engineis delivered to a. condenser 17. The condensate is conducted back to the hot well 1, completing the circuit.

'I'he burner and boiler construction is of a well known type in which the coils are arranged in spaced relation around a burner grating 18, the preheating coil being outermost from the burner and the vaporizing coil being adjacent the hottest part of the burner. A casing 19 of fire resisting material surrounds the boiler coil and the burner. The burner grating 18 is mounted on a vaporizing and mixture conducting casing 20. A preferable form of burner casing is shown and claimed in Patent No. 1,900,003 issued March 7, 1933, to Earl C. Walker and the present applicant. An air conduit 21 is connected with the casing 20. An

extension 22 is adapted to connect the conduit 21 with a source of air under pressure, such for example as a fan. A damper 23 in the form of a butterfly valve is mounted on a shaft 24, which extends through the conduit 21. A lever 25 rig- 50 idly secured to the shaft 24 on the outside of the conduit provides a meansfor operating the damper. The lever 25 is pivotally connected to .the plunger 26 of a solenoid 27. A second lever 28 is also rigidly-attached to the shaft 24. The 65 end of the lever 28 is connected by a link 29 to a lever 30.v The lever 30 is rigidly attached to a small damper 31 positioned-in a conduit 32. The conduit 32 is connected to the conduit 21 on the `high pressure side of the damper and leads 70 to the pilot burner which is similar in construction to the main burner consisting primarily of a vaporizing casing 33 and a burner grating 34. The pilot burner is positioned immediately below the main burner and is providedk for maintaining the casing 20 ata temperature sufcient to vaporize fuel being delivered thereto when the main burnerv is to beput into operation.

Fuel is supplied to the main burner by a nozzle 35 in the, conduit 21 and by a similar nozzle 36 in 80 the conduit 32 leading to the pilot burner. Oil is supplied to the nozzle 35 by a motor driven pump 37. rl'he pump draws liquid from a main fuel reservoir 38 and forces it through a regulating device 39 which governs the pressure at which 85 fuel oil is supplied through the pipe 40 to the main nozzle 35. A valve 41 in the pipe 40 provides an additional means for controlling the flow of fuel. The oil by-passed from the-regulating device 39 is delivered into an auxiliary reservoir 42. From the reservoir 42 oil is supplied by gravity flow through the pipe 43 to the nozzle 36 in amounts regulated by the valve 44. An overflow 45 is provided from the auxiliary reservoir 42 whereby exf cess oil is conducted back to the main reservoir 38. I

An electrically operated controlling system is provided for the air and oil` system described above. A source of direct current 46 is utilized for operating the electrical controls. A line 47 100 leads from one side of the supply to one end of the coil of the solenoid 27. From the other end of the coil aline 48 leads to a contact 49. A temperature operated sylphon 50 is positioned at the top of the storage drum 10. The sylphon is adapted to operate the contact lever 51 to make and break contact between the contact 49 and a similar contact 52. A pressure operated switch 53 communicating with the storage drum above the water level is also positioned in the same circuit and is adapted to make or break the circuit. A line 56 connects the switch 53 with one side of the current supply line 46. A second circuit connected with current supply lines 46 joins in series a ,motor 57 adapted to operate the pump 37 and a switch 58 mounted on the shaft 24 of the main damper. A third circuit consisting of current supply lines 59 leads to a resistance heater 60 positioned below the pilot burner.

In the operation of this device the resistance heater 60 is put into operation, thereby heating the vaporizing and mixture conduit 33 of the pilot burner. Air is supplied through the extension 22 of the air conduit 21. The dampers 23 and 31 are so arranged that some air will be supplied to the pilot burner even when the main damper is closed. Oil from the reservoir 42 is delivered by gravity to the pilot burner and combustion is initiated in this burner. As we assume that the boiler was started from a' cold condition, the switch operated by member 53 Will be closed, as pressure in the storage drum is low. The lever 51 Will also be in closed or contacting position, as the temperature of the storage drum is low. It will, therefore, be understood that the circuit is closed and that current will flow through the lines 47 and 48. By this ow of current the solenoid is operated, opening the damper 23. 'I'he switch 58 on the shaft 24 of the damper is arranged to close the circuit of motor 57 when the damper has been opened a predetermined distance. When the switch closes the electrical circuit in which it is positioned, the motor 57 is put into operation and also the pump 37, which it drives. Fuel is then delivered from the tank 38 through the regulator 39 to the nozzle 35 in the main air conduit 2l. The pump is so constructed that it has a capacity of more than the maximum requirements of the main burner. Oil by-passed from the regulator is delivered to the auxiliary reservoir 42, providing a supply for feeding the pilot burner. Any excess in the auxiliary reservoir is returned through the overflow to the main reservoir. The interconnection between the main damper and the damper in the air supply conduit leading to the pilot burner is for the purpose of maintaining a substantially constant pressure difference between the air inside and the products of combustion outside the burner. This construction is shown more fully in the patent previously referred to, and forms a part of the invention claimed in that application.

It is to be understood that applicant has shown only a preferred embodiment of his improved control system and that he claims as his invention any modication falling Within the scope of the appended claims.

What is claimed is:

1. A combustion system comprising a main burner, an air conduit connecting a source of air under pressure with said burner, a valve in said conduit, an electrical control means for operating said valve, electrically operated means for supplying oil to the burner, means operated by the closing of said valve to break the circuit operating the oil supply means, an electrical circuit for operating the valve control means, said means being adapted to open the valve when the circuit is closed, and a switch operable to break said circuit.

2. A combustion system comprising a main burner, an air conduit connecting a source of air under pressure with said burner, a damper in said conduit, an electrical control means for operating said damper, electrically 1 operated meansA for supplying oil to the main burner, means operated by the closing of said damper to break the circuit operating the oil supply means, a pilot burner, means for supplying fuel to said burner, an air conduit leading to said burner, a damper in said conduit, said damper being interconnected to the main damper.

3. A combustion system comprising a main burner, anair conduit connecting a source of air under pressure with said burner, a damper in said conduit, an electrical control means for operating said damper, electrically operated means for supplying oil to the main burner, means operated by the closing of said damper to break the circuit operating the oil supply means, a pilot burner, means for supplying fuel to said burner, an air conduit leading to said burner and connected to the same source as the conduit to the main burner, a damper in said conduit, said damper being interconnected to the main damper whereby it is moved toward closed position when the main damper is closed thereby preventing an excess of air pressure in the pilot burner.

GUSTAF W. ENGSTROM. 

